Avoid synchronously recalculating the nonFastScrollableRegion when the ScrollableArea set changes
Created attachment 138120 [details]
I can probably construct a layout test for this too (but it'll be a bit convoluted)
Comment on attachment 138120 [details]
Clearing flags on attachment: 138120
Committed r114778: <http://trac.webkit.org/changeset/114778>
All reviewed patches have been landed. Closing bug.